ICICI Bank — False charge for demat account

Address:

Pune, Maharashtra, 411061

I am using ICICI bank from almost 2 years. I have a Demat account in ICICI bank for 2 years now. When I checked my bank transactions and I found that there is one debit transaction 'DMC/IN[protected] DP CHGS TILL M AR-17'---- INR 805.62'. When I created the Demat account, I was not told about the DP charges, it was told me by the ICICI representative that it is free of cost and it will never be charged and also I did not get any message alert in my registered mobile or my registered mail id.
This is completely unacceptable and please refund my amount.